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Re: Why do we need lua in-tree again? Yet another call for actual evidence, please. (was Re: Moving Lua source codes)

Hi Jeff,

On Thu, Oct 17, 2013 at 1:26 PM, Jeff Rizzo <> wrote:
> On 10/14/13 1:46 PM, Marc Balmer wrote:
>>> It is entirely plausible to me that we could benefit from using Lua in
>>> base, or sysinst, or maybe even in the kernel.  But that argument must
>>> be made by showing evidence of real, working code that has compelling
>>> benefits, together with confidence in its robustness -- not by saying
>>> that if we let users do it then it will happen.
>> There is real word, real working code.  In userland and in kernel space.
>>   There are developers waiting for the kernel parts to be committet, so
>> they can continue their work as well.
> *Where* is this code?  The pattern I see happening over and over again is:
> NetBSD Community: "Please show us the real working code that needs this"
> mbalmer:  "the code is there!" (pointer to actual code not in evidence)
> I do not doubt that something exists, but the onus is on the person
> proposing the import to convince the skeptics, or at least to make an actual
> effort.  I see lots of handwaving, and little actual code.  YEARS after the
> import of lua into the main tree, I see very little in-tree evidence of its
> use.
> In fact, what I see is limited to :
> 1) evidence of lua bindings for netpgp.
> 2) evidence of some tests in external/bsd/lutok
> 3) the actual lua arc in external/mit/lua
> 4) gpio and sqlite stuff in liblua
> 5) some lua bindings in libexec/httpd ("bozohttpd")
> 6) two example files in share/examples/lua
> 7) the luactl/lua module/lua(4) stuff you imported yesterday

...and counting. There is also ongoing working happening =).

> Am I missing something major here?  The only actual usage I see is netpgp
> and httpd;  the rest is all in support of lua itself.  I do not see evidence
> that anyone is actually using lua in such a way that requires it in-tree.
> When you originally proposed importing lua back in 2010, you talked a lot
> about how uses would materialize.  It's now been 3 years, and I just don't
> see them.  If I am wrong about this, I would love some solid pointers to
> evidence of my wrongness.
> Now you're using very similar arguments for bringing lua into the kernel;  I
> would very much like to see some real, practical, *useful* code
> demonstrating just why this is a good thing.  Beyond the 'gee, whiz' factor,
> I just don't see it.

Lua is a tool, not an end in itself. I think that you are formulating
a chicken-and-egg problem: we need the basic support for then having
applications, and we need applications for then having basic support.
Sure, we do not *need* a script language interpreter embedded in the
kernel, as we do not need a specific file system. But I do not get why
we should not. There is current development of applications being done
right now. Also, there is a few interesting works that used Lunatik in
Linux [1, 2] that could be done more easily now in NetBSD just because
we have the right environment for that. That is not about needing, but
it is about supporting a certain kind of agile development,
prototyping, customization and experimentation in the NetBSD kernel
(how could it be hurtful?). I think that is why we *should* (not need)
have this on the tree. IMHO.



> +j

Lourival Vieira Neto

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